MONMOUTH (AP) — Maine farmers are concerned about a sudden increase in the numbers of an invasive fruit fly being trapped.

The one-sixteenth of an inch long spotted wing drosophila, a native of northern Asia, was first detected in Maine last summer in small numbers. But this summer traps in Monmouth have bagged thousands per week.

Experts say the females cut small holes in ripening fruit to lay eggs. The fruit, to the naked eye, can look fine for another day or two but quickly becomes inedible.

David Handley, vegetable and small fruit specialist for the University of Maine Cooperative Extension, tells the Sun Journal the bug is a “game changer” particularly worrisome for the blueberry crop.

Fighting the insect could cost farmers who may have to spray pesticides twice a week.